Silicon-organic isocyanurates, such as 1,3,5-tris(trialkoxysilylpropyl)-isocyanurate are known from the U.S. Pat. No. 3,821,218. These compounds, that can be used as adhesive agents, develop through the trimerization of the corresponding silylorganoisocyanates. The isocyanates, on the other hand, are prepared by effecting a reaction between silylorganohalides and metal cyanates, such as potassium cyanate.
Thermally hardenable compositions, consisting essentially of (a) a silicon-hydrogen compound with at least two hydrogen atoms bonded to the silicon atom and (b) at least one isocyanuric acid compound in the form of a trialkenylisocyanurate or of a derivative thereof, are known from the German Published Patent Application 24 21 038. These compositions can also contain an addition polymerization catalyst or this type of catalyst and a radical polymerization catalyst. The components (a) and (b) are usually mixed and hardened in an essentially equimolar ratio. During the hardening, products are formed that have good thermal resistance, mechanical strength and adhesive property.
A method for preparing organopolysiloxane elastomers is known from the German Published Patent Application 36 31 125, wherein substances that are cross-linkable as a result of the attachment of Si-bonded hydrogen to SiC-bonded vinyl groups are cross-linked. The substances contain an additive to improve the adherence of the elastomers to the bases, on which they are produced. This additive can be, inter alia, an organosilicon compound that is obtained through the hydrosilylation of triallylisocyanurate with an organosiloxane of the formula HSi(CH.sub.3).sub.2 [OSi(CH.sub.3).sub.2 ].sub.n H, in which n is a whole number with a value of 1 to 5. Isocyanurate-containing organosilicon compounds are thereby formed, whereby each isocyanurate nitrogen is bonded via a (CH.sub.2).sub.3 grouping to a Si-H-functional polysiloxane chain, in particular --Si(CH.sub.3).sub.2 OSi(CH.sub.3).sub.2 H.